音频，FFT 不起作用

class Main
{
    WaveFileReader reader;
    short[] sample;
    Complex[] tmpComplexArray;
    public Main()
    {
        //read in wav, to raw data in byte array then to short array.
        reader = new WaveFileReader("C:''Users''minford''Downloads''English_Subtitles_.wav");
        byte[] buffer = new byte[reader.Length];
        reader.Read(buffer, 0 , buffer.Length);
        sample = new short[reader.Length];
        for (int n = 0; n < buffer.Length; n += 2)
        {
            sample[n] = BitConverter.ToInt16(buffer, n);
        }


        // short array to complex
       Complex[] complexData = new Complex[sample.Length];
        for (int i = 0; i < complexData.Length; i++)
        {
            Complex tmp = new Complex(sample[i],0);
            complexData[i] = tmp;

        }
        //to get first 500 for testing.
        tmpComplexArray = new Complex[500];
        for (int i = 0; i < 500; i++)
        {
           Complex a = new Complex(complexData[i]);
           tmpComplexArray[i] = a;
        }
        //run FFT
        FourierTransform.DFT(tmpComplexArray ,FourierTransform.Direction.Forward);
        //print result
        for (int i = 0; i < complexData.Length; i++)
        {
            Console.Write(complexData[i]);
        }
    }
}

}

我在使用 AForge 的 FFT 时遇到了这个问题。这是正确的使用方式吗？返回的复数(目前仅返回前 500 个(每次将第二个数字定为 0。